Top definition
When a man stretches out his scrotum sack and bounces his penis off it like a monkey jumping on a trampoline. This technique was created by two brothers from Mass.
Jack loves playing with his sack, his favorite manuver is the monkey on a trapoline.
by Bro#2 January 12, 2006
Get the mug
Get a monkey on a trapoline mug for your daughter-in-law Beatrix.